Both were about a sort of (un?)official challenge to find XSS vectors capable of bypassing the famous PHPIDS tool, a game both Sirdarckcat and I already found quite funny in the beginning of past July and, according to Mario Heiderich, helped him in hardening his PHPIDS filters.

At any rate, Sirdarckcat's post ended like this:

I'm sure that Gareth Heyes, and Giorgio Maone will be the next to find some vectors

Notice that -- quite obviously -- you will need to disable NoScript (or at least disable its anti-XSS protection and allow both hackademix.org and php-ids.org), if you want to get some joy from the links above.